An autonomous vehicle is a vehicle that is capable of sensing its environment and navigating with little or no user input. An autonomous vehicle senses its environment using sensing devices such as radar, lidar, image sensors, and the like. The autonomous vehicle further uses information from global positioning systems (GPS) technology, navigation systems, vehicle-to-vehicle communication, vehicle-to-infrastructure technology, and/or drive-by-wire systems to navigate the vehicle.
Vehicle automation has been categorized into numerical levels ranging from Zero, corresponding to no automation with full human control, to Five, corresponding to full automation with no human control. Various automated driver-assistance systems, such as cruise control, adaptive cruise control, and parking assistance systems correspond to lower automation levels, while true “driverless” vehicles correspond to higher automation levels.
For highly autonomous vehicles there is a need for the braking system to monitor its own functionality to replace the brake system monitoring that would otherwise be done by a human driver in a conventionally operated vehicle. Specifically, the autonomous vehicle needs to monitor the braking system performance for hydraulic leaks and compliance degradations due to the presence of air in the hydraulic fluid. These issues are diagnosed by observing and comparing the measured brake fluid volume that is pumped into the brake system to the measured system pressure. This testing can be done both passively and actively. Passive tests would observe the reaction of the pedal during normal driving maneuvers, but may not be a sufficient maneuver to robustly evaluate the system. Active tests are more effective and will give the most robust testing results.
Accordingly, it is desirable to provide systems and methods that allow the brake control system to test the braking system for hydraulic leaks and compliance degradations. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.